1. Field of the Invention
This invention relates to stabilization of catalysts which normally become unstable at elevated temperatures of desired catalytic reactions. The invention promotes long term stabilization of lithium catalysts at reaction temperatures above about 600.degree. C. to obtain higher conversion in reactions such as catalytic oxidative coupling of hydrocarbons to produce higher molecular weight compounds and oxydehydrogenation to produce unsaturated hydrocarbon compounds.
2. Description of Related Art
Use of lithium on basic metal oxides to catalyze chemical reactions such as oxidative coupling of aliphatic hydrocarbons to produce higher molecular weight products is known. J. B. Kimble and J. H. Kolts, Oxidative Coupling of Methane to Higher Hydrocarbons, Energy Progress, Vol. 6, No. 4, pp 226 (1986). Oxidative dehydrogenation of aliphatic hydrocarbons to form unsaturated hydrocarbon chains using lithium basic metal oxide catalysts is known. U.S. Pat. No. 4,950,830. When large amounts, over about 1 weight percent, lithium has been added to the basic oxides, lithium has had a tendency to vaporize and leave the catalyst/support at temperatures higher than about 600.degree. C. thereby reducing the activity of the catalyst. J. B. Kimble et al., supra. Therefore, there is a need for a thermal stabilizer for lithium catalysts to preserve their activity when used to catalyze chemical reactions at temperatures higher than about 600.degree. C.